Description: Tamron AF 18-250mm f/3.5-6.3 Di II LD IF Lens
Experience all the power of a big 14X zoom ratio and take pleasure an astonishing 2 zooms in 1. The Tamron high-powered 18-250mm zoom lens a dream for
photographer's come true with just one lens having the capacity to shoot
wide angle
plus
ultra
telephoto without changing lenses.
If you need a low light lens, this isn't it. If your primary objective is
to take pictures in low light situation such as
weddings
and
concerts,
in the 18-200mm range you need 2 lenses, get the 18-50mm f/2.8 Sigma or
Tamron 17-50 VC and a 70-200mm f/2.8 lens instead.
Typical 35mm film cameras almost always needed two lenses to take care of the 28-400mm length range. However the Tamron' high-powered 13.9x zoom, the world's highest powered zoom provides plenty of photographic liberty of this colossal range in just one compact lens.
This 18-250mm zoom Di-II lens delivers an approximate 27-387mm 35mm equivalent range when mounted on DSLR cameras featuring a 24mm x 16mm or less size imager sensor.
Digitally Integrated Design (Di), is a title Tamron includes on their lenses with optical systems engineered to compliment performance characteristics of DSLR cameras. DI Lenses include the following advantages: Reduced peripheral light fall-off, Improved Resolution, chromatic aberration reduction, ghosting and flare compensation
Superzoom
The term hyperzoom or superzoom is used to promote photographic zoom lenses with unconventionally large focal length factors, typically more than 4× and ranging up to 15×, e.g., 35 mm to 350 mm. The largest ratio for digital SLR cameras is held by the Tamron 18–270 mm, giving 15×. Some Digital Camera Review by Gene Wrights have even larger zoom ratios up to 35×. For movie and television use, Panavision holds the record with their 300X HD Lens.
While superzoom lenses have improved greatly in recent years, they still have a number of drawbacks in comparison with shorter-range zooms and prime lenses. Most notable is the much increased likelihood of significant distortions of the image at both extreme ends of the range. Other potential problems include smaller maximum aperture and poorer autofocus performance
Nov 20, 2011
Following is a list of superzoom lenses, used for 135 format in SLRs or for APS format in DSLRs. The minimal factor used here is 5×
or more. A 28–200 mm has a 75° to 12.3° angle of view, a 28–300 mm (or an 18–200 mm for an APS DSLR) has
an 11.1x 75° to 8.2°
Alternative Superzoom Lenses
Features
• Aspherical Lens
A
lens whose curved surface does not conform to the shape
of a sphere. An aspheric element is often called
an aspherical lens.
The asphere's more complex surface profile can eliminate
spherical aberration and reduce other
optical aberrations compared to a simple lens. A single aspheric lens can often replace a much more complex multi-lens system. The resulting device is smaller and lighter, and possibly cheaper than the multi-lens design. Aspheric elements are used in the design of multi-element wide-angle and fast
normal lenses to reduce aberrations.
• Di-II Series Design
Design has been improved by adding a gold-colored band between the focus and zoom rings to enhance the appearance and make it stand out as a Di-II lens. The rubber patterns of the zoom and focus control rings have been improved at the same time to compliment the digital camera design style and to provide better handling.
Di-II Lenses are designed for digital SLR cameras with
smaller imagers
• Low Dispersion lens elements
(LD
Glass to reduce
chromatic aberration for sharper images) Aspherical - contains aspherical elements (compensates for
spherical aberration and
distortion, making for better performance with fewer elements (and As a result allowing for smaller, lighter lenses)
• Internal Focusing
Internal focusing lens (also known as IF) is a
photographic lens design in which focus is shifted by moving the inner lens group or groups only, without any rotation or shifting of the front lens element. This makes it easy to use, for example, a screwed-in
polarizing filter or a petal shaped lens hood. During
macro photography, using an internal focus lens reduces the risk of the front of the lens accidentally hitting the subject during focusing as the front element does not move.
• World's Most Powerful Zoom, featuring 14X zoom range
• Equivalent to 27-387mm (13.9X)
• Like two lenses in one (28-200 + 200-400)
• Designed exclusively for DSLRs with smaller imagers
• Sophisticated optical system for high quality digital images
• Compact & lightweight (3.3 in./15.2 oz.)
Lens Includes
•
Flower-shaped Lens Hood
•
Tamron U.S.A. 6-Year Warranty
